Sinks in general, whether kitchen, commercial, bar, utility (slop), etc. and other fluid holding vessels such as bathtubs and tanks, all use some type of drain assembly to maintain fluid and then discharge the fluid. For instance, a basket drain is commonly installed in the bottom of a sink because it is the least expensive way of stopping water from draining. In some commercial applications, a lever or twist drain is used in lieu of the simple basket drain. This not only works better (water does not leak as fast as with a basket drain), but also allows an individual to control the drain mechanism from under the sink, rather than reaching down into the water to allow it to drain. However, this is quite costly and sometimes cumbersome in comparison to the simple basket drain. Other systems require the user to stick his or her hand into a sink of hot or dirty water to allow drainage. Oft times an unsightly strainer lying sideways in the bottom of a sink is the only way to prevent accidental stoppage of the drain during normal use of the sink.
There are also numerous drain assembly designs which are controlled remotely from the drain, i.e. from above the sink, bathtub, etc. Such systems are usually unduly complicated or they are unreliable in preventing unwanted leakage through the drain or under the sink itself.